Academic literature on the topic 'Micrococcus roseus'

Gryllotalpa africana (Beauvois) is a successful group of detritus feeder therefore it is an important both for their roles in carbon cycling in the environment and converting organic decaying material in to biofuel. Hence, bacterial diversity and relationship were explored from the mole cricket G.africana (Beau) to show ideal symbiotic association. The analysis and characterization of gut micro biota of G.africana (Beau) revealed the presence of 10 species and two genera of bacteria viz. Acidiphilium rubrum, Dienococcus proteolyticus, Sporosarcina ureae, Micrococcus varians, Micrococcus kristinae, Acetobactrium, Alcaligenes eutrophus, Micrococcus roseus, Micrococcus lylae, Sporosarcina, Citrobacter amalonaticus and Corynebacterium xerosis. All the species and genera were confirmed by observing their morphological features of the colony and various biochemical tests. These results indicate that the presence of mole cricket specific bacterial lineages implies relationship of gut microbes and their host mole cricket. The outcome of this work indicted that the gut bacterial fauna of G.africana shows the species-rich with greater diverse communities which might be providing resistance to invasion of pathogenic bacteria. DOI: http://dx.doi.org/10.3126/ijls.v6i1.5949

The poultry feeds were obtained from 20 different poultry pens and their microbial contents were assessed. The antibiotics resistance patterns of the bacterial isolates were also determined. The bacterial count ranged from 5.0 × 103 to 1.76 × 106 cfu/g while the fungal count ranged from 3.5 × 104 to 1.9 × 105 cfu/g. The bacterial species isolated were Streptococcus salivarius, Streptococcus pyogenes, Micrococcus luteus, Micrococcus varians, Micrococcus roseus, Staphylococcus aureus, Staphylococcus saprophyticus and Staphylococcus hominis, while the fungal species isolated were Saccharomyces cerevisisae, Fusarium oxysporum, Penicillium sp., Humicola grisea, Aspergillus fumigatus, Hansenula sp. and Humicola fuscoatra. All the bacterial isolates were resistant to ceftazidime and cefuroxime and all the isolates were resistant to at least three antibiotics. Ofloxacin produced the highest zone of inhibition, followed by gentamicin, and then erythromycin. The presence of some pathogenic microorganisms in the poultry feeds revealed high level of contaminations. It is recommended that poultry feeds should be made from good quality grains and it should be prevented from environmental or other contamination.

A Spiranthera odoratissima A. St.-Hil (manacá) é utilizada popularmente como depurativo do sangue, nas afecções renais e hepáticas (chá das folhas) para dores musculares, de estômago, de cabeça, e disfunções hepáticas (chá das raízes). O objetivo desse trabalho foi avaliar a composição química do óleo essencial e a atividade antimicrobiana do óleo essencial, do extrato etanólico bruto e frações obtidos das folhas de S. odoratissima contra bactérias Gram positivas e negativas, e Candida albicans. O extrato bruto das folhas foi obtido por maceração seguido de concentração em rotaevaporador e as frações por partição em coluna filtrante. O pó das folhas foi submetido à hidrodestilação em aparelho de Clevenger e o óleo essencial obtido foi analisado por CG/EM. A atividade antimicrobiana foi avaliada pelo método da diluição em ágar para determinar a concentração inibitória mínima (CIM). Os constituintes majoritários do óleo essencial foram β-cariofileno (20,64%), γ-muuroleno (17,70%), biciclogermacreno (14,73%), e δ-cadineno (13,40%). No estudo da atividade antimicrobiana de S. odoratissima, os principais resultados foram obtidos contra Staphylococus epidermidis (extrato etanólico bruto, CIM de 0,098 mg/mL), C. albicans (fração hexano, CIM de 0,049 mg/mL), Bacillus cereus (diclorometano, CIM de 0,098 mg/mL), Micrococcus roseus (fração acetato de etila, CIM 0,049 mg/mL), e M. roseus, Micrococus luteus, B. cereus e C. albicans (fração metanol, CIM de 0,391 mg/mL).

The importance of replacing synthetic pigments with natural types is increasing day by day in the food industry due to the harmful effects of some synthetic pigments. Microorganisms are a major source of natural pigments, which nowadays have attracted the attention of researchers. In this study, carotenoid pigments were produced by Micrococcus roseus and Rhodotorula glutinis, and some of their biological properties such as antimicrobial, antioxidant, anticancer, and anti-inflammatory activities were evaluated. Given the results, bacteria, especially gram-positive bacteria, had higher sensitivity to the pigments extracted from M. roseus (PEM) and R. glutinis (PER) compared to molds so that Bacillus cereus and Alternaria citri had the highest and the lowest sensitivity, respectively. PER showed a higher antioxidant activity compared with PEM in the various methods of measuring antioxidant activity. In vitro and in vivo anti-tumor-promoting activities of PER were measured significantly more than PEM ( P <0.05). Both pigment extracts remarkably inhibited the 12- O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation, so that ID50 (50% inhibitory dose) of PEM and PER were 0.22 and 0.09 mg/ear, respectively.

博士
輔仁大學
食品營養學系
91
The objectives of the study were to evaluate the effects factors influencing the growth of Bifidobacterium spp., study the effect of probiotics, including Bifidobacterium infantis, Bifidobacterium longum, Lactobacillus acidophilus, Lactobacillus brevis, Lactobacillus plantarum, as well as Escherichia coli O157:H7, Micrococcus roseus, Micrococcus luteus, Vibrio parahaemolyticus and Staphylococcus carnosus in phosphate buffer solutions containing nitrate on the reduction of nitrate to nitrite and on the activity of nitrate reductase, examine the extraction, purification and properties of E. coli O157:H7 nitrate reductase, and finally study effect of B. longum and E. coli O157:H7 on the formation of N-nitrosodimethylamine (NDMA). The acid production and bacterial counts of B. breve, B. infantis and B. longum were better than those of B. adolescentis in MRS broth and 11% non-fat dry milk. B. adolescentis and B. breve died off after storage at 7℃ for 16 and 12 days, respectively. B. infantis and B. longum grew very well even after 30 days, with bacterial counts of 107 - 108 CFU/mL. The reduction rate of bacterial counts of Bifidobacterium spp. was slower under anaerobic storage. Probiotics did not possess the ability to reduce nitrate to nitrite. The reduction of nitrate of E. coil O157:H7 and M. roseus was the highest, followed by S. carnoseus and V. parahaemolyticus. M. roseus and E. coli O157:H7 showed optimum reduction activity when pH value was at 7 and cell density was 4 log CFU/mL after 24 h incubation. Very little nitrite was formed when pH and temperature were below 5 and 15℃, respectively. About 80% nitrate was reduced in pH 7 phosphate buffer solution containing 503-2,006 mg/L nitrate. Co-culture of B. longum with each culture of E. coli O157:H7, V. parahaemolyticus and M. roseus in pH 7 phosphate buffer solutions containing 2,000 mg/L of nitrate for 24h did not inhibit nitrate reduction. When the co-culture trials were carried out in both pH 6 and pH 5 phosphate buffers, B. longum effectively inhibit the nitrate reduction caused by the three bacteria. Growth of B. longum in pH 7 phosphate buffer solution before inoculating each of the three bacteria also substantially inhibited nitrate reduction, resulting in the formation of a small amount of nitrite. No nitrate reduction was observed after incubation of each test bacterium in spent B. longum phosphate buffer solution (pH 4.8) for 24 h. When the pH 7- adjusted spent B. longum phosphate buffer solution was employed, the reduction of nitrate caused by the three bacteria was reestablished, however, the formation of nitrite was much lower than that in pH 7 phosphate buffer solution. The reduction of nitrate was found in each extract of celery stem, celery leaf, radish and hot dog incubating with E. coli O157:H7 and M. roseus. No nitrate reduction was observed when B. longum was growing in the extracts. Co-culture of B. longum in the extracts with each culture of E. coli O157:H7 and M. roseus slightly inhibited the nitrate reduction. The reduction of nitrate reached a plateau after 24 h incubation of E. coli O157:H7 and M. roseus in extracts of radish at 25-37℃. To obtain the same level of nitrate in the extracts, both bacteria took 6-7 days at 15℃ incubation and 14-15 days at 7℃. Probiotics did not show any nitrate reductase activity in pH 7 broth media containing 2,000 mg/L nitrate after 24 h incubation at 37℃. However, E. coli O157:H7, M. roseus and S. carnosus demonstrated higher nitrate reductase activities, with 0.117, 0.109, 0.061 units/mL, respectively. The enzyme activities of M. luteus and V. parahaemolyticus were somewhat lower. The nitrate reductase activities of E. coli O157:H7 and M. roseus in aerobic and facultatively anaerobic incubations were higher than those in anaerobic condition. Higher nitrate reductase activity was also obtained in TSB containing 500-2,000 mg/L nitrate. Maximum nitrate reductase activities were also attained when pH of substrate and incubation temperature were 7 and 25-37℃, respectively. The nitrate reductase activities reached a plateau in pH 7 TSB containing 2,000 mg/L nitrate after 18 h incubation of E. coli O157:H7 and M. roseus at 37℃. The E. coli O157:H7 crude nitrate reductase was purified by 60% ammonium sulfate precipitation, Sephacyl S-300 gel filtration and finally Q Sepharose ion exchanges column chromatography. The purity of the enzyme was increased by 5.28 fold, and the recovery was 11.5%. Molecular weight of the purified enzyme was about 549, 560 Da estimated from Native-PAGE. The stable pH value of the crude enzyme was 7.0, and the stable temperature of the purified enzyme was 30℃. Metallic ions, including Ca2+, Na+ and Na2MoO4 did not change enzyme activity, whereas Cu2+ and Fe3+ showed negative effect. The enzyme activity remained about 70.6% as it was stored at 7℃ for 30 days and lost all activity at 15℃ for 10 days and 25-37℃ for 6 days. The Km from Lineweaver-Burk plot of the purified enzyme was 9.32×10-4 mg/mL, and Vmax 1.1658 unit/mL. Formation of NDMA was enhanced with lowering pH and increasing nitrite and dimethylamine concentrations in pH 4-7 phosphate buffer solutions. The NDMA level in pH 4 phosphate buffer solution after 48h reaction was significantly higher than that in pH 5 solution. Maximum level of NDMA was obtained when the reaction was carried out at pH 4 for 18 h. However, it required 24 h to reach the highest level at pH 5. E. coli O157:H7, rather than B. longum, was found to form NDMA in phosphate buffer solution containing nitrate and dimethylamine. About 0.3-2.6 mg/L NDMA was attained after 24 h growth of E. coli O157:H7 in phosphate buffer solution containing nitrate and dimethylamine with higher production at pH 5 and 6. The formation of NDMA was inhibited by high level of nitrate in buffer solution at pH 4.